Pipe lining apparatus



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United States Patent() 3,462,821 PIPE LlNlNtG APPARATUS Donald V. Cours,.lohn K. McGee, and Harold L. Lalferty,

Houston, Tex., assignors to Gray Tool Company, Houston, Tex., acorporation of Texas @riginal application Nov. 29, 1965, Ser. No.510,274, now Patent No. 3,359,624, dated Dec. 26, 1967. Divided and thisapplication Aug. 22, 1967, Ser. No. 678,125

Int. Cl. B23p 19/02 US. Cl. 29-200 4 Claims ABSTRACT F THE DISCLOSUREThere is disclosed apparatus for lining the bore of a pipe by outwardlydeforming an inserted liner into contact with the pipe bore. Theapparatus includes end closures for closing olf both ends of the pipeybore and for receiving the initially protruding ends of the liner.Crcumferential seals are provided between both end closures and theliner and one of the end closures has a port for admitting linerdeforming pressurized fluid to the bore of the liner.

This invention relates to the lining of pipes or tubular members and inparticular to a structure utilizing uid pressure for radially expandinga tubular liner into engagement with the internal walls of a tubularmember.

This application is a division of my copending application, Ser. No.510,274, tiled Nov. 29, 1965, now U.S. Pat. 3,359,624, issued Dec. 26,1967.

It has heretofore been proposed to effect a lining of tubular members orpipes by utilizing fluid pressure to radially expand a relativelyductile and thin Wall liner into engagement with a more rigid tubularmember. It has further been proposed to line the tubular member by rstdisposing the liner longitudinally within the tubular member, engagingexpander tools to each end of the liner and then introducing fluidpressure into the liner to expand it. However, the structures andmethods heretofore proposed have not been entirely satisfactoryparticularly when the radial expansion that the liner must undergo forsecuring it to the outer tubular member results in significant reductionor contraction of the length or axial dimension of the liner.Understandably, the axial contracting movement of the liner relative tothe outer tubular member must be permitted without undesirable loss offluid pressure within the liner so that the radial expansion step may beeffectively performed. In other Words, the operating and necessary lluidpressure for eX- pansion must be maintained Within the liner until theexpanding step terminates notwithstanding the magnitude of theconcomitant axial contracting movement of the tubular liner relative tothe outer tubular member during expansion.

Accordingly, an important object of this invention is to provide a novelstructure utilizing fluid pressure t0 expand a tubular liner intoengagement with a tubular member.

A still further object resides in the development of a novel apparatusfor lining pipes, in the manner referred to, utilizing the fluidpressure introduced into the liner t0 establish and maintain fluidpressure seals at each end of the liner whereby the nature of the axialcontracting movement of the expanding liner can be desirably controlledwithout impairing the fluid tightness of the seals.

Another object of the present invention is the provision of apparatusfor expanding a tubular liner into engagement with a tubular memberwhich obviates the necessity for using a mechanical expander tool, whichcan be performed rapidly and With a high degree of success and 3,462,821Patented Aug. 26, 1969 ICC which can be effected while the pipe beinglined is in a generally horizontal condition.

A further object of the invention involves the provision of meansbetween the pipe being lined and the liner for venting air from theshrinking annulus between these members as the lining is deformed intoplace to thereby avoid entrapping air between the pipe and the liner.

These and further objects of the present invention as well as theprinciples and scope of applicability of the invention will become moreclearly apparent during the course of the following detailed explanationof the elements of the embodiment of the invention as depicted in theannexed drawing:

In the drawing:

The figure is a longitudinal sectional view through a pipe and apparatusaccording to the present invention, parts being in elevation and partsbeing broken away for more efficient demonstration of detail; the linerbeing shown before deformation at the left and after deformation at theright in the figure.

Internally lined pipes, conduits or other tubular members have numerousapplications in many industries and environments. They are particularlyuseful when the eX- terior and interior of the tubular members are notexposed to the same conditions such as would occur in the handling offluids where a good corrosion resistant surface is needed on the insideof the pipe whereas the exterior thereof is not exposed to or in contactwith a particularly harmful or corrosive environment and hence, need notpossess the same corrosion resistant properties as the interior of thepipe. One eld of application is in oil well operations where it may bedesirable and/or necessary for certain pipe sections to be adequatelyprotected internally against the possibly harmful action of fluids owingtherethrough. It will be evident from the following description however,that the novel means of the invention are suitable for lining pipes orconduits irrespective of the particular industry or environment in whichthe pipe will be used.

Furthermore, the invention is not intended to be limited to anyparticular type of pipe or conduit, although it will be shown anddescribed for illustrative purposes as being used to provide innerlinings on individual pipe sections adapted to be connected or coupledtogether with sealing means to form an extended conduit length whereinthe pipe sections and sealing means may be of the general type disclosedin Patents 2,766,829, 2,766,- 998 and 2,766,999.

The pipe 10 illustrated in the figure is known in the art as a spoolbecause both ends thereof are anged with radially directed anges 12, 14of increased section modulus and diameter from the remainder 0f thepipe. As shown, the spool 10 comprises a central conduit section 16 ofuniform cross-sectional shape to which adapter hubs 1S, 20 or the likeare butt -welded at 22. The pipe 10 has a throughbore 24 which flaresadjacent each radially directed annular end surfaces 26, 27 to formannular sealing ring seats 28, 30. Each flange 12, `14 is provided witha tapered annular wedging sur-face 32 which faces the center of the pipeand enlarges in diameter toward -the nearest end 26. As stated beforethe end configuration of the pipe shown is exemplary since the presentinvention is applicable to the lining of pipe with substantiallydifferent end treatment and even to pipe having different end rtreatmentat opposite ends of the same length of pipe. The term pipe should beconstrued broadly as it is used in the present specification to includenot only elements for conducting fluid, 'out also elements for confiningfluid. For instance, the pipe 10 could comprise the center section of apressure vessel or a section of distillation column or the like.

To give an indication of scale, the exemplary pipe 10 has an externalradius of 2.5 inches at the fianges 12, 14. The principles of thepresent invention are, however, applicable to pipes of both larger andsmaller radii than the example.

Lining of the pipe 10 involves disposing in the pipe a tubular liner 34of Monel, stainless steel or the like, initially having an outsidediameter smaller than the inside diameter of the pipe then defor-mingthe liner so that its outer peripheral wall 36 is in intimate contactwith the inner peripheral wall 38 of the pipe including the wall of thebore 24 and of the ared ring seats .28, 30.

In lining a pipe 10 according to the present invention, the unlined pipeis placed on a support rack (not shown) so that it is nearly horizontal,but preferably slightly inclined at about one degree of elevation sothat the end 27 is slightly higher than the end 26 for reasons to becomeapparent hereinafter.

It is essential that the pipe inner peripheral wall and liner outerperipheral wall be clean and dry in order to prevent rippling andcorrosion, that might otherwise occur due to the encapsulation offoreign material between the pipe and liner. It is also advantageous toclean and dry the liner inner peripheral wall so that it will notcontaminate the fluid used to deform the liner or cause excessive wearof valving and the like employed in control and recovery f the fluid.

The underformed liner 34 preferably is substantially longer than thepipe as indicated in the drawing. The end regions 40 of the liner arereduced so that they taper toward the ends. The reduction may beperformed using a sizing tool or the like after the undeformed liner 34has been slid into the pipe.

Next an end fixture 42, 44 is tightly secured to each end of the pipe toclose off the pipe bore and surround the protruding liner portions. Inthe embodiment shown, each of 'the end fixtures 42, 44 comprises avessel end 46 having a well 48 opening toward its inner end. A length ofconduit 50 is butt welded to the vessel end inner end at 52 and at itsopposite end is butt welded to an adapter hub S4. These end fixtures maybe made in one piece rather than being welded together. Each adapter hub54 includes a radiallly outwardly directed annular fiange S6 having anannular end face 58 and a tapered annular wedging surface 60 `whichfaces the associated conduit 50 and enlarges in diameter toward theassociated end 58. The conduits 50 have bores 62 that proceed as axialextensions of the vessel end wells 48, the same bores extending at 64axially into the adapter hubs 54. Approaching the end faces S8 the bores64 each decrease in diameter at 66 then flare at 68 and finally becomegenerally cylindrical at 70. Intermediate each decreased diameterportion 66 a circumferential, radially, inwardly opening groove 72 isformed. Each groove 72 receives an O-ring seal 74.

The end fixtures 42, 44 are fitted over the protruding ends of the liner34 and slid until their ends S8 abut the respective ends `26, 27 of thepipe. The tapering of the end regions 40 causes the `O-rings 74 to slipover and rollingly resiliently engage `the outer peripheral surface ofthe liner without being damaged.

When the end surfaces 58 have been brought into abutment with the endsurfaces 26, 27, the end fixtures 42, 44 are secured to the pipe 10using means such as expansible contractile segmental clamps 76 of thetype more fully discussed in the above-mentioned patents. The clamps 76have opposed wedging surfaces 78, 80 which engage the end fixture andpipe surfaces 32 and 60 to draw thesemembers toward one another and thesurfaces 58 and 26, 2'7 into tight engagement.

It should now be noticed that the lower end fixture 42 is drilled andtapped or the like longitudinally of the fixture and tangentially withthe bottom of the well side wall to form a filling port 82. The endfixture 42 is also drilled and tapped or the like radially intermediatethe ends of the well sidewall at its top to form a pressurization port84. Both the ports 82 and 84 open outwardly of the fixture 42.

The upper end fixture 44 is drilled and tapped or the like radially nearthe base or outer end of the well sidewall at its top to form a bleedport 86. The bleed port 86 opens outwardly of the fixture 44.

After the clamps 76 have been installed, a quick fill fitting S8 issecured to the fixture 42 in communication with the filling port 82. Thefitting 88 preferably includes a rapidly openable-rapidly closable valve90 interposed in a conduit 92 having a quick connect-quick disconnectcoupling 94. A pressure line fitting 96 is secured to the fixture 42 incommunication with the pressurization port 84. The fitting 96 iscommunicated to the high pressure side of a pump (not shown) andpreferably includes a rapidly openable-rapidly closable valve 98interposed in a conduit 100 having a quick connect-quick disconnectcoupling 102. Similarly bleed fitting 104 is secured to the fixture 44in communication with [the bleed port `86. The fitting 104 preferablyincludes a rapidly openablerapidly closable valve 106 interposed in aconduit 108 having a quick connect-quick disconnect coupling 110. Incertain instances provision could be made for ermanently connecting thequick fill pressurization and bleed lines to the `end fixtures.

Upon completion of the fittings just mentioned the quick-fill valve 90is opened to a fiuid supply while the pressurization valve 98 is closedand the bleed valve 106 is open. The fluid employed in the instancebeing discussed is water although other tiuids such as oil orpolyethylene glycol could be used. As the water fills lining and thefixture 42, 44 bores air is forced out of the system via the bleed port.Since the latter is at the higher end of the apparatus air bubbles willtend to rise toward the bleed port. When water begins to issue from thebleed port, the quick fill valve is closed and then the bleed valve isclosed.

The high pressure pump connected to the port 84 is then communicated tothe system by opening the valve 98. Upon achieving about 20 percent offinal pressurization, the system is bled again using the bleed port 86.At this point a check is also made to determine if the O-rings haveformed a complete seal about the liner and against the end fixtures. Ifthey have not, and the system were further pressurized, Huid could leakinto the annulus between the pipe and the liner and out through the ventholes 112, a plurality of which are formed radially through the pipe inorder to allow air in the annulus to escape as the liner is deformedradially outwardly against the pipe. The leakage of deforming fiuidduring pressurization could, if the O-ring seals were sufficientlyleaky, also prevent the building up of sufficient pressure to effectdeformation of the liner. When it has been determined that the O-ringseals are not leaking, for instance by taking readings on a pressuregauge (not shown) temporarily secured to one of the vent holes 112, thebleed valve is reclosed and the pressure pump utilized to bring thesystem to final pressure for instance 20,000 p.s.i.g. whereupon theliner undergoes plastic deformation from the condition shown to the leftof the break 114 in the figure. The finally pressurized condition ismaintained for about one minute to ensure that the liner has beendeformed into intimate contact with the inner peripheral wall of thebore of the pipe 10 and end fixtures 42, 44 at all points between theO-rings 74.

The high pressure pump is then cut off from communication with thesystem by closing the valve 98 and the system bled by opening the bleedvalve 106.

The pressurization, quick fill and bleed lines are then disconnectedfrom the end fixtures, the clamps 76 removed and the end fixtures 42, 44slid axially away from one another leaving the lined pipe with excessliner 116 protruding from each end.

It should be apparent that as the lining is deformed radially outwardlyduring pressurization it shrinks somewhat axially. This accounts for therelative shortness of the excess liner 116 at the right in the figurecompared to the excess prior to deformation as seen at the left in thefigure. The O-ring seals 74 are of importance during deformation of theliner since they bot-h provide circumferential rolling support for theliner as it contracts axially and maintain a seal between the linerexterior peripheral surface and the end fixture inner peripheralsurfaces. The long excess portions 116 are provided so that the flaringwhich will provide the sealing ring seats does not occur so near theends of the liner that there would be a substantial prospect that, inthe process of deformation, leakage would occur past the seals 74 orthat rippling of the liner adjacent the ends would take place.

To finish the lined pipe the protruding excess liner is cut off flushwith the pipe ends and the sealing ring seats finished to size by a seatrolling tool, grinding or the like.

IDepending upon the use for which the lined pipe is intended it may befurther processed for instance by heat treatment exposure to chemicalsolutions or coated outside and/or inside with an anti-oxidant, paint orthe like.

It should now be realized that the embodiment of the invention discussedherein efficiently accomplishes each of the inventiions objects asstated in the specification and clearly illustrates the principles ofthe present invention. Because the embodiment shown and described can beconsiderably modified without departing from these principles or failing.to accomplish these objects, the present invention should beinterpreted as encompassing all such modifications as are within thespirit and scope of the following claims.

We claim:

1. Apparatus for lining a pipe throughbore with a pressure expandedliner comprising: a first end fixture having means defining a cavitytherein opening outwardly of one end of said first end fixture forreceiving a liner protruding end; means for securing the first end xtureto one end of a pipe having a liner protruding from said one end of thepipe so that the liner protruding end is received in the cavity; meansfor providing a circumferential seal between the liner and the cavity ofthe first end fixture; means for enclosing the opposite end of saidliner from said liner protruding end, the means for enclosing theopposite end of said liner from said liner protruding end comprising asecond end fixture having means defining a cavity therein openingoutwardly of one end of said second end fixture for receiving a linerprotruding opposite end; means for securing the second end fixture tothe opposite end of a pipe from said pipe one end having the linerprotruding from said opposite end of the pipe so that the linerprotruding opposite end is received in the cavity; and means forproviding a circumferential seal between the liner and the cavity of thesecond end fixture; one of said first end fixture and second end fixturehaving means for admitting a fluid therethrough into the liner and meansfor pressurizing said fluid to deform the liner outwardly intoengagement with the pipe.

2. The apparatus of claim 1 further comprising means defining at leastone radially inwardly opening circumferential channel in each endfixture in communication with the cavity thereof; the means forproviding a circumferential seal between the liner and the cavities ofthe first and second end fixtures comprising a resilient O-ring receivedin and protruding radially inwardly from each of said channels.

3. The apparatus of claim 1 wherein the means of securing the first andsecond end fixtures to the ends of the pipe comprise radially expansibleand contractile clamps having opposed annular wedging surfaces foraxially drawing each end fixture axially toward the pipe.

4. The apparatus of claim 1 wherein the other of said first end fixtureand means for enclosing the opposite end of said liner from said linerprotruding end from said one of said first end fixture and thelast-mentioned means has means for bleeding air from said liner as theliner is being filled with fiuid.

References Cited UNITED STATES PATENTS 895,412 8/1908 Badger 29-4212,460,580y 2/ 1949 Huber. 2,479,702 8/ 1949 Rood 29-523 X 2,748,463 6/1956 Mueller 72-62 X THOMAS H. EAGER, Primary Examiner U.S. Cl. X.R.

